Process for making tubular needlefelted material

ABSTRACT

A tubular needlefelted material is formed from a continuous web of fibres which is wound as an overlapping helix to form the tube. As the web is wound parallel reinforcing threads are supplied to wrap the tube. The wound web and threads are needlefelted and the needlefelted tube thus produced is progressively advanced in the direction of the axis of the tube. Preferably the threads lay to one side of the web so as to be located near the inner surface of the finished tube.

llnited States Patent [191 Wilde PROCESS FOR MAKING TUBULAR NEEDLEFELTEDMATERIAL [76] Inventor: John Clarke Wilde, PO. Box 14,

Bury, England, BL9 611D [22] Filed: July 15, 1974 [21] Appl. No.:488,559

[52] U.S. Cl 28/72.2 R [51] lint. Cl. 130411-11 18/00 [58] Field ofSearch 28/4 R, 72.2 R; 138/144 [56] References Cited I UNITED STATESPATENTS 2,748,805 6/1956 Winstead 138/144 3,375,561 4/1968 Ford 28/72.2R 3,424,204 1/1969 Sato 138/144 3,477,898 11/1969 Buff et a1. 28/722 REriksson 28/722 R Dilo 28/722 R Primary Examiner-Lot1is K. lRimrodtAttorney, Agent, or Firm-James E. Nilles [5 7] ABSTRACT A tubularneedlefelted material is formed from a continuous web of fibres which iswound as an overlapping heliit to form the tube. As the web is woundparallel reinforcing threads are supplied to wrap the tube. The woundweb and threads are needlefelted and the needlefelted tube thus producedis progressively advanced in the direction of the axis of the tube.Preferably the threads lay to one side of the web so as to be locatednear the inner surface of the finished tube.

12 Claims, 3 Drawing Figures US. Pamm Get. 7,1975 3,9,93

PROCESS FOR MAKING TUBULAR NEEDLEFELTED MATERIAL BACKGROUND OF THEINVENTION This invention concerns an improved needlefelted material andin particular a needlefelted material produced in tubular form.

Tubular needlefelted materials are known and basically one manner ofproduction comprises the continuous feeding of a web of fibres to passover spaced parallel rolls with at least one needlebar reciprocabletowards and away from the web. The needled web is progressively moved ina direction parallel to the roll axis so that an extended tube iscreated and its thickness is built up with the web feed. This manner ofproduction is illustrated and described in US. Pat. No.

3,508,307 based on German Application No.

l6,607,65.1. Another manner of production of tubular needlefeltedmaterial is shown in US. Pat. No. 3,758,926 and another in US. Pat. No.3,540,096.

Whilst such a machine as that briefly described above or as shown in US.Pat. No. 3,758,926, or US. Pat. No. 3,540,096 produces a felt which hasmany useful properties there are requirements for felts which cannotadequately be met by the felt normally produced in the manner set outabove, primarily because the felt has neither the wearing properties northe dimensional stability that are required.

One use for tubular felts of high quality is in the leather industry asa sleeve for a sammying machine. Such a sleeve is typically cms indiameter, 15 mm thick and 180 cms long. At present most of the sammyingsleeves in use are produced from woven material and whilst such a sleeveis effective for the purpose for which it is designed it may be that ifimproperly used the pattern of the weave of the fabric may be impressedupon the leather being treated. Clearly unless the sleeve is of constantdensity and strength and has a smooth surface sammying operations may beadversely affected.

Also in the leather industry there is a call for sleeves for setting outmachines and these sleeves are required to withstand pressure which insome cases may be of the order of tons across the width of a settingmachine roll of some 180 cms in length.

In some cases it is thought to be advantageous to produce a tubular feltmaterial which can, after production, be cut to form a flat pad and ofcourse such a pad can be used in many industries and situationsproviding the initially produced tubular felt has the requisite strengthand other physical properties.

It is therefore an object of the present invention to produce a feltedmaterial in tubular form in which the inherent strength of the felt isgreater than that which has hitherto been achieved whilst at the sametime ensuring that the properties of the felt, such as surfacesmoothness, density and the like are substantially unaffected.

SUMMARY or THE INVENTION Accordingly the present invention provides aprocess for manufacturing an improved tubular needlefelted materialcomprising:

a. forming a continuous web of fibres;

b. feeding the web as a helix to create a tube with adjacent turns ofthe helix overlapping:

c. causing strengthening strands to wrap said tube helically as the webis fed;

d. needlefelting said tube and strands; and

e. progressively advancing; the needlefelted tube in the direction ofthe axis of the tube. whereby there is formed a needlefelted tube withheli' cally wound strengthening strands located within the wallthickness of the tube.

BRIEF DESCRIPTION OF THE DRAWINGS.

The invention will now be described further, by way of example only,with reference to one practical form thereof, and with reference to theaccompanying drawings in which:

FIG. 1 is an enlarged view on the line I I of FIG. 2.

FIG. 2 is a plan view on a slightly reduced scale taken in the directionof line II II of FIG. 1.

FIG. 3 is an end elevation view in reduced scale taken on the line IIIIII of FIG. ll.

DESCRIPTION OF THE PREFERRED EMBODIMENT A dry carded web 10 of syntheticfibres is shown being fed (arrow A) and wound in a helical fashion withoverlap on the circumferentially ribbed core tube 11 supported on anoverhung shaft 12 and rotating as indicated by arrow B. The web buildsup to form a sleeve 13.

Reinforcing threads 14, which may be filament polyamide or spun naturalthreads for example are taken from bobbins I5 and are wound with the web10 on to the core tube 11. The threads build up to form a row 16 ofreinforcing threads which lies nearer to the inside wall of the finishedtube than the outside wall.

Similarly threads 14' are taken from bobbins to form a further row 16 ofreinforcing threads. These may lay at the centre of the wall of thefinished tube. In FIGS. 1 and 2 the letter W designates the width of thecarded web 10 and the letter p designates the width occupied by aplurality of strands or threads 14.

Above the core tube 11 there is located a reciprocating arrow D) needleboard 17. The sleeve is drawn off the free end of the core tube 11 inthe direction of arrow C by a hub 39 turned by a motor 38 at the samerotary speed as the sleeve (arrow E). The motor is carried on a plate 32movable on a frame (not shown) axially of the sleeve as indicated byarrow F. The sleeve is clamped to the hub 39 by three clamping anvils 41(only one shown) movable as indicated by arrow G. The needlefeltedmaterial is progressively drawn off the machine by a rotating tailstockarrangement which grips the sleeve in pneumatic jaws, the speed ofrotation being identical to that of the sleeve, and this unit iscontinuously being driven away from the fibre input and needling unit bya variable speed chain drive unit, as detailed in FIG. 7 US. Pat. No.3,758,926. Alternatively the sleeve may be drawn off through a pair ofrotating nip rollers, being subsequently wound onto a spool (FIG. 1 U.S.Pat. No. 3,758,926).

A typical spacing of threads 14 lies preferably within the range of l to50 mm.

The density of needling may be made variable to produce a light 3) ftsleeve 13 or a hard dense one, the former being very useful forfiltering.

In lieu of threads 14 it is possible to use, as a reinforcing strand,tape or scrim. The tape may be of closely woven or open weave structure.

The invention could also be used to produce a larger diameter sleeve bywinding a web helically over two spaced rollers in the manner disclosedin the said US. Pat. No. 3,508,307.

The increase in dimensional stability of the sleeves or tubular fabricproduced, according to the invention, renders the fabric particularlysuitable for use as a sammying sleeve since the outer surface of thetube presents the desired smooth surface and the reinforcement due tothe yarns or tape incorporation in the tube enhances the effective lifeof the tube when being used as a sammying sleeve. In the case in whichthe reinforcement is provided adjacent to the inner surface of asammying sleeve the reinforcement does not affect the outer surface ofthe sleeve and thus it has no adverse effect on the leather beingtreated.

Tubular reinforced fabrics produced as described above may be used forother purposes such as sleeves for setting out machines used in theleather industry and in fact as roller sleeves for use in otherindustries.

Additionally the fabric may be used in tubular form as bearing materialand it may also be used, when cut longitudinally and opened out intoflat form as a press pad or bearing material.

The material may be impregnated and typically it may be impregnated witha lubricant such as graphite to function as a bearing material. Thematerial may also be impregnated with a resin. The method ofimpregnation is such that a liquid resin is introduced through apressurized jet spray system into the center of the tube and is directedat the wall of the sleeve where it is absorbed by the needlefeltedmaterial. The point of impact of resin onto the surface is varied alongthe length of the sleeve by a reciprocating device. The control of thedegree of penetration of the resin is to some extent dependent upon thetype of resin and is known to masters of the art of textile finishing.The function of the impregnation is to give the sleeve increasedresistance to longitudinal extension and thickness compaction during useas well as increasing abrasion resistance. These are factors in theimprovement of working life and result from a degree of chemical bondingof the fibres due to the impregnation.

Where a sleeve is built up between two spaced rollers the inside of thesleeve may be sprayed with a resin, preferably so that the resin doesnot reach the outer regions of the sleeve. This can provide furtherstrengthening without disturbing the nature of the outer surface of thesleeve. Sleeves produced according to the invention not only have therequisite surface smoothness and density, but also have a strength, dueto the reinforcement given by the yarns or tape, which serves to resistdeformation by way of extension diametrically or lengthwise.

In the case in which a sleeve is required to be tightly held in positionon a roller it is possible to produce the sleeve with inherent shrinkageproperties by the use of heat shrinkable fibres so that when the sleeveis in position on the roller its size can be reduced to cause it to gripthe roller tightly by the application of heat, such as a hot waterspray.

A sleeve made in accordance with the invention and needles to produce adense felt and made of heat shrinkable fibres will, when cut to form aflat pad and hot pressed to flatten, create a very dense high strengthpad.

I claim:

1. A process for manufacturing an improved tubular needlefelted materialcomprising:

a. forming a continuous web of fibres of predetermined width;

b. feeding the web as a helix to create a tube with adjacent turns ofthe helix overlapping by a major part of said predetermined width;

c. causing a plurality of strengthening strands to wrap said tubehelically as the web is fed, said strands occupying a width which isless than said predetermined width of said web;

d. needlefelting said tube and strands and e. progressively advancingthe needlefelted tube in the direction of the axis of the tube, wherebythere is formed a needlefelted tube with helically wound strengtheningstrands located within the Wall thickness of the tube.

2. The process of claim 1 in which the strands comprise parallelfilaments.

3. The process of claim 2 in which the strands are provided by a tape.

4. The process of claim 2 in which the strands are provided by scrim.

5. The process of claim 1 in which the strands are fed, relative to theweb of fibres, so as to lay to one side of the web thereby forming aneedle felted tube with helically wound strengthening strands which lienearer to the inside wall of the tube than the outside wall.

6. The process of claim 1 in which an additional step of causingstrengthening strands to wrap said tube helically is performed wherebythere is formed a needlefelted tube with helically wound strengtheningstrands located at two depths within the wall thickness of the tube.

7. The process of claim 1 in which the carded fibres are of heatshrinkable material.

8. The process of claim 7 in which the tube formed by the process is cutto produce a sheet and the sheet is heat pressed to flatten and shrinkit.

9. The process of claim 1 in which the needlefelted tube is impregnatedby spraying with a substance which adds a desired property thereto.

10. The process according to claim 9 wherein said substance comprisesgraphite.

11. The process according to claim 9 wherein said substance comprisesresin.

12. A process for manufacturing tubular needlefelted materialcomprising:

a. forming a continuous web of base fibres of predetermined width;

b. feeding said web over spaced rollers having free ends as a helix withadjacent turns overlapping by a major part of said predetermined width;0. needlefelting the overlapping turns to form a sleeve;

d. causing a series of parallel strengthening filaments and to wrap saidsleeve helically as it is being formed, f. causing the sleeve to moveaxially as web is fed so said filaments occupying a width which is lessthan that the needlefelted wrapped sleeve leaves the rolsaidpredetermined width of said web; lers at the free ends thereof. e.needlefelting the wrapped sleeve; 5

1. A process for manufacturing an improved tubular needlefelted materialcomprising: a. forming a continuous web of fibres of predeterminedwidth; b. feeding the web as a helix to create a tube with adjacentturns of the helix overlapping by a major part of said predeterminedwidth; c. causing a plurality of strengthening strands to wrap said tubehelically as the web is fed, said strands occupying a width which isless than said predetermined width of said web; d. needlefelting saidtube and strands and e. progressively advancing the needlefelted tube inthe direction of the axis of the tube, whereby there is formed aneedlefelted tube with helically wound strengthening strands locatedwithin the wall thickness of the tube.
 2. The process of claim 1 inwhich the strands comprise parallel filaments.
 3. The process of claim 2in which tHe strands are provided by a tape.
 4. The process of claim 2in which the strands are provided by scrim.
 5. The process of claim 1 inwhich the strands are fed, relative to the web of fibres, so as to layto one side of the web thereby forming a needle felted tube withhelically wound strengthening strands which lie nearer to the insidewall of the tube than the outside wall.
 6. The process of claim 1 inwhich an additional step of causing strengthening strands to wrap saidtube helically is performed whereby there is formed a needlefelted tubewith helically wound strengthening strands located at two depths withinthe wall thickness of the tube.
 7. The process of claim 1 in which thecarded fibres are of heat shrinkable material.
 8. The process of claim 7in which the tube formed by the process is cut to produce a sheet andthe sheet is heat pressed to flatten and shrink it.
 9. The process ofclaim 1 in which the needlefelted tube is impregnated by spraying with asubstance which adds a desired property thereto.
 10. The processaccording to claim 9 wherein said substance comprises graphite.
 11. Theprocess according to claim 9 wherein said substance comprises resin. 12.A process for manufacturing tubular needlefelted material comprising: a.forming a continuous web of base fibres of predetermined width; b.feeding said web over spaced rollers having free ends as a helix withadjacent turns overlapping by a major part of said predetermined width;c. needlefelting the overlapping turns to form a sleeve; d. causing aseries of parallel strengthening filaments to wrap said sleeve helicallyas it is being formed, said filaments occupying a width which is lessthan said predetermined width of said web; e. needlefelting the wrappedsleeve; and f. causing the sleeve to move axially as web is fed so thatthe needlefelted wrapped sleeve leaves the rollers at the free endsthereof.